Michael Moorcock's Jerry Cornelius

I wanted to see if anyone could confirm something I just read on the TV Tropes page for The Cornelius Chronicles: "Moorcock also made the character (Jerry Cornelius) available to other writers, making Jerry a sort of open-source character nearly 40 years before Jenny Everywhere."

So, is there actually an Eternal Champion in the Public Domain waiting to be used? I mean, yeah...it's Jerry Cornelius, not Elric or any of the good Eternal Champions, but hey...